gvle: using boost::program_options to manage cli

Replace the old C style code with boost::program_options class to manage
the command line interface. (closes #44)
utils: remove boost::mutex static member in Trace

The boost::mutex static member of Trace::Pimpl is now a member of Trace
since Trace is used as a singleton (Closes #45)
update for win32

- fix the building of vle.dll using flag VLE_DLL
- remove static vle library (remove BUILD_SHARED_LIBS option)
- build a libgvle.dll fo win32
- template: use static boost libs
- template: add cmake macro for test building
- Define the cmake FindPackage scripts : VLE, VLE_DEPS, GVLE, GVLE_DEPS
- Modify gvle.pc to find libgvle for win32